Midterm 1 Flashcards
1
Q
Perception
A
Conscious experience that results from stimulation of the senses
“Higher order”
2
Q
Perceptual process
A
A sequence of steps leading from the environment to perception of a stimulus, recognition of the stimulus, and action with regard to the stimulus
3
Q
Sensation
A
Involves simple “elementary” processes that occur right at the beginning of a sensory system
4
Q
Distal stimulus
A
“Distant”; out there up in the environment
5
Q
Proximal stimulus
A
The stimulus on the rectors. In vision, this would be the image on the retina
6
Q
Principle of representation
A
Everything a person perceives is based not on direct contact with stimuli but on representations of stimuli that are formed on the receptors and the resulting activity in the persons neurons
7
Q
Sensory receptors
A
Cells specialized to respond to environmental energy, with each sensory system’s receptors specialized to respond to a specific type of energy
8
Q
Visual pigment
A
A light sensitive chemical that reacts to light and allows visual receptors to transform light energy into electrical energy
9
Q
Transduction
A
The transformation of one form of energy to another form
10
Q
Neural processing
A
The changes in signals that occur as they are transmitted through the maze of neurons
11
Q
Primary receiving area
A
Area of the cerebral cortex that first receives most of the signals initiated by a senses receptors. For example the occipital cortex is the site of primary receiving area for vision, and the temporal lobe is the site of the primary receiving area for hearing
12
Q
Cerebral cortex
A
A 2-mm thick layer that contains the machinery for creation perceptions, as well as other functions, such as language, memory, and thinking
13
Q
Occipital lobe
A
Primary receiving areas for vision
14
Q
Temporal lobe
A
Primary receiving area for hearing
15
Q
Parietal lobe
A
Primary receiving area for skin senses- touch,temperature, and pain
16
Q
Frontal lobe
A
- Receives signals from all of the senses
- Plays an important role in perceptions that involve the coordination of information received through two or more senses
17
Q
Visual form Agnosia
A
An inability to recognize objects
18
Q
Action
A
The final behavioural respond
19
Q
Knowledge
A
Any information that the perceiver brings to the situation
20
Q
Rat- man demonstration
A
Shows how recently acquired knowledge (“that pattern is a rat”) can influence perception
21
Q
Categorize
A
To place objects into categories; an example of how knowledge acquired years ago can influence the perceptual process
22
Q
Bottom up processing
A
(Data processing) processing that is based on the stimuli reaching the receptors; “incoming data”
23
Q
Top- down processing
A
(Knowledge based processing) processing that is based on knowledge
24
Q
Oblique effect
A
People see vertical or horizontal lines better than lines oriented obliquely
25
Stimulus- perception relationship
Relates stimuli to behavioural responses
26
Physiology perception relationship
Relates physiological responses and behavioural responses
27
Grating acuity
The smallest width of lines that subjects can detect
28
Stimulus physiology relationship
Relationship between stimuli and physiological responses
29
Cognitive influences on perception
How the knowledge, memories, and expectations that a person brings to a situation influences his or her perception
30
Thresholds
Measure the limits of sensory systems; they are measures of minimums
31
Psychophysics
The study of the relation between mental and physical
32
Method of limits
A psychophysical method for measuring threshold in which the experimenter presents sequences of stimuli in ascending and descending order
33
Classical psychophysical methods
The methods of limits, adjustment, and constant stimuli, described by Fechner, that are used for measuring thresholds
34
Absolute threshold
The smallest stimulus level that can just be detected
35
Difference threshold
The smallest difference between two stimuli that enables us to tell the difference between them
36
Magnitude estimation
A psychophysical method in which the subject assigns numbers to a stimulus that are proportional to the subjective magnitude of the stimulus
37
Perceived magnitude
A perceptual measure of stimuli, such as light or sound, that indicates the magnitude of experience
38
Recognition
The process of categorizing that gives it meaning
39
Reaction time
The time between presentation of a stimulus and the persons reaction to it
40
Phenomenological report
Observer describes what he or she perceives, describing what is out there
41
Electromagnetic spectrum
A band of energy ranging from gamma rays at the short wave end of the spectrum to AM radio and AC circuits at the long-wave end of the spectrum
42
Wavelength
The distance between the peaks of the electromagnetic waves
43
Visible light
The energy within the electromagnetic that humans can perceive, has wave length ranging from about 400 to 700 nm, short wavelengths blue, middle green, long yellow, orange, and red
44
Pupil
The opening through which light reflected from from objects in the environment enters the eye
45
Cornea
The transparent focusing element of the eye that is the first structure through which light passes as it enters the eye. The cornea is the eyes major focussing element
46
Lens
The transparent focusing element of the eye through which light passes after passing through the cornea and the aqueous humor. The len's change in shape to focus at different distances is called accommodation
47
Retina
The network of neurons that covers the back of the eye and that contains the receptors for vision
48
Rod
A cylinder -shaped receptor in the retina that is responsible for vision at low levels of illumination
49
Cone
Cone shaped receptors in the retina that are primarily responsible for colour vision and detail vision
50
Outer segments
The part of the receptor that contains light sensitive chemicals called visual pigments that react to and trigger electrical signals
51
Fovea
Contains only cones; when we look directly at an object the objects image falls on the fovea
52
Peripheral retina
Includes al, the retina outside of he fovea, contains both rods and cones (many more rods than cones, but does contain many cones)
53
Macular degeneration
Most common in older people; destroys the cone rich fovea and a small area that surrounds it, which creates a blind region in central vision, so when a person looks directly at something, he or she loses sight of it
54
Retinitis pigmentosa
A degeneration of the retina that is passed from one generation to the next; attacks the peripheral Rod receptors and results in poor vision in the peripheral visual field. Eventually, in severe cases, the foveal cone receptors are also attacked, resulting in complete blindness
55
Blind spot
The area in the retina where there are no receptors as it is the place where the nerve fibers that make up the optic nerve leave the eye
56
Accommodation
The change in the lens's shape that occurs when the ciliary muscles at the front of the eye tighten and increase the curvature of the lens so that it gets thicker
57
Presbyopia
As people get older, their ability to accommodate decreases due to hardening of the lens and weakening of the ciliary muscles, and so the become unable to accommodate enough to see objects, or read at a close range
58
Myopia
Nearsightedness- an inability to see distant objects clearly; when optical system prints parallel rays of light into focus at a point in front of the retina
59
Refractive myopia
The cornea and/ or the lens bends the light too much
60
Axial myopia
Eyeball is too long
61
Hyperopia
Farsightedness- can see distant objects clearly but have trouble seeing nearby objects because the focus point for parallel rays of light is located behind the retina, usually because the eyeball is too short
62
Transduction
The transformation of one form of energy into another form or energy
63
Isomerization
When the retinal part of the visual pigment molecule absorbs light, the retinal changes its shape from being bent to straight. This change in shape creates a chemical chain reaction that activates thousands of charged molecules to create electrical signals in receptors
64
Dark adaptation
Process of increase sensitivity in the dark
65
Light- adapted sensitivity
The sensitivity measured in the light
66
Dark- adapted sensitivity
The sensitivity at the end of dark adaptation
67
Rod monochromats
People who have no cones because of a rare genetic defect
68
Rod- cone break
Place where the rods begin to determine the dark adaptation curve
69
Visual pigment bleaching
The change in shape and separation from the Opsin of the retinal part of the visual pigment molecule causes the molecule to become lighter in colour
70
Visual pigment regeneration
The process of reforming the visual pigment molecule (rods take longer than cones)
71
Detached retina
When a person's retina becomes detached from the pigment epithelium, a layer that contains enzymes necessary for pigment regeneration.
72
Spectral sensitivity
The eyes sensitivity to light as a function of the lights wavelength
73
Monochromatic light
Light of a single wavelength
74
Measure cone sensitivity curve
Have subject look directly at a test light so that it stimulates only the cones in the fovea
75
Measure Rod spectral sensitivity
Measuring sensitivity after the eye is dark adapted and presenting test flashes in the peripheral retina, off to the side of the fixation point
76
Purkinje shift
The enhanced perception of short wavelengths during dark adaptation
77
Absorption spectrum
A plot of the amount of light absorbed versus the wavelength of the light
78
Cell body
Contains mechanisms to keep the cell alive
79
Dendrites
Branch out from the cell body to receive electrical signals from other neurons
80
Axon (nerve Fiber)
Filled with fluid that conducts electrical signs,s
81
Resting potential
-70 mV ; axon at rest, no signals
82
Action potential
+40 mV; signal transmitted
83
Propagated response
Once the response is triggered, it travels all the way down the axon without decreasing in size
84
Refractory period
The interval between the time one nerve impulse occurs and the next one can be generated in the axon
85
Spontaneous activity
Action potentials that occur in the absence of stimuli from the environment
86
Rising phase of action potential
This increase in potential from -70 mV to + 40 mV (sodium rushes into axon)
87
Falling phase of action potential
Increase in negativity from + 40 mV back to -70 mV (potassium rushes out of axon)
88
Excitatory response
Occurs when the inside of the neuron becomes more positive (depolarization)
89
Inhibitory response
Occurs when the inside of the neuron becomes more negative (hyperpolarization)
90
Neural circuits
Interconnected groups of neurons
91
Neural convergence/ convergence
Occurs when a number of neurons synapse onto a single neuron
92
Visual acuity
The ability to see details
93
Lateral inhibition
Inhibition that is transmitted across the retina
94
Chevreul illusion/ staircase illusion
The perceived light and dark bands at borders, which are not present in the actual physical stimuli
95
Receptive field
The area on the receptor surface that when stimulated affects the firing of that neuron
96
Center- surround organization
The area in the center of the receptive field responds differently to light than the area of the surround center field
97
Excitatory area
Increases firing
98
Inhibitory area
Decreases firing
99
Center- surround antagonism
The competition between the center and surround regions of a center surround receptive field, caused by the fact that one is excitatory and the other is inhibitory. Stimulating center and surround areas simultaneously decreases responding of the neuron, compared to stimulating the excitatory area alone
100
Visual receiving area, striate cortex, V1
The place where signals from the retina and LGN first reach the cortex
101
Simple cortical cells
Cells with side by side receptive field
102
Complex cells
Respond best to cells of a particular orientation when moving across the entire receptive field
103
End- stopped cells
Fire to moving lines of a specific length o to moving corners or angles
104
Feature detectors
Simple, complex, and end stopped cells; fire in response to specific features of the stimulus
105
Selective adaptation
Firing causes neurons to eventually become fatigued, or adapt
1) neurons firing rate decreases
2) the neuron fires less and that stimulus is immediately presented agai
106
Selective rearing
If an animal is reared in an environment that contains on,y certain types of stimuli, then Neurons that respond to these stimuli will become more prevalent
107
Neural plasticity/ experience dependent plasticity
The response properties of neurons can be shaped by perceptual experience
108
Problem of Sensory coding
How neurons represent various characteristics of the environment
109
Specificity coding
An object could be represented by the firing of s specialized neuron that responds only ro that object
110
Population coding
The representation of a particular object by the pattern if firing of a large number of neurons
111
Sparse coding
Occurs when a particular object is represented by a pattern of firing of only a small group of neurons, with the majority of neurons remaining silent
112
Retinotopic map
The electronic map of the retina on the cortex
113
Cortical magnification
Apportioning of a large area of the cortex to the small fovea
114
Location columns
Perpendicular to surface of cortex so that all neurons within a location have their receptive fields at the same location on retina
115
Orientation column
Each column containing cells that respond best to a particular orientation
116
Hyper column
A location column with all of its orientation columns
117
Object discrimination problem
Monkey shown an object, presented with two choice task which included "target" object and another non-target; reward picking target
118
Landmark discrimination problem
Monkeys task remove cover of the food well that was closest to the tall cylinder
119
What pathway
The pathway leading from the striate cortex to the temporal lobe, responsible for determining objects identity (ventral pathway)
120
Where pathway
The pathway leading from the striate cortex to the parietal lobe, responsible for determining an objects location (dorsal pathway)
121
Double dissociatio a
Two people: one damage A B fine, other damage B A fine
122
Prosopagnosia
Damage to temporal lobe that causes difficulty recognizing the faces of familiar people
123
Parahippocampal place area
Activated by picture depicting indoor and outdoor scenes
124
Extrastriate body area (EBA)
Activated by picture or bodies and parts of bodies (but not by faces)
125
Mind- body problem
How do physical processes like nerve impulses become transformed into the richness of perceptual experience?
126
Expertise hypothesis
Proposes that our proficiency in perceiving certain things can be explained by changes in the brain caused by long exposure, practice, or training
127
Inverse projection problem
The task of determining the object responsible for a particular image on the retina
128
Viewpoint variance
Ability to recognize an object seen from different viewpoints
129
Grouping
Process by which visual events are "put together" into units or objects
130
Segregation
Process of separating one area or object from another
131
Principles of perceptual organization
Determine how elements in a scene become grouped together
132
Principle of good continuation
Points that, when connected, result in straight or smoothly curving lines are seen as belonging together, and the lines tend to follow the smoothest path
133
Principle of pragnaz/ good figure/ simplicity
Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible
134
Principle of similarity
Similar things appear to be grouped together
135
Principle of proximity or nearness
Things that are near each other appear to be grouped together
136
Principle of common fate
Things that are moving in the same direction appear to be grouped together
137
Principle of common region
Elements that are within the same region of space appear to be grouped together
138
Principle of uniform connectedness
A connected region of the dame visual properties is perceived as a single unit
139
Perceptual segregation
The perceptual separation of one object from another
140
Figure- ground segregation
When we see a separate object, it is usually seen as a figure that stands out from ite background (ground)
141
Reversible figure ground
It can be perceived alternatively either as two dark blue faces looking at each other in front ppt of gray background, or a gray vase on a dark blue background
142
Gist of a scene
The general description of the type of scene
143
Persistence of vision
The perception of a visual stimulus continues for about 250 ms after the stimulus is extinguished (eliminated by visual masking stimulus)
144
Physical regularities
Regularly occurring physical properties of the environment
145
Light from above assumption
We usually assume that light is coming from above, because light in the environment, including the sun and most artificial light, usually come from above
146
Semantic regularitie
Characteristics associated with activities that are common in different types of scenes
147
Scene schema
Knowledge of what a given scene typically contains
148
Bayesian inference
Proposed that our estimate of the probability of an outcome is determined by two factors: 1) prior probability 2) likelihood of outcome
149
Prior probability/ prior
Our initial estimate of the probability of an outcome
150
Likelihood of outcome
The extent to which the available evidence is consistent eight he outcome
151
Binocular rivalry
If two eyes receive totally different images observer perceives either the left eye image or the right eye image, but not both at the same time
152
Structural encoding
Based on relationship between vowel activation and structural characteristics of a scene, such as lines, contrasts, shapes, and textures
153
Semantic encoding
Based on relationship between vowel activation and the meaning or category of a scene
